Field of the Invention
The invention is in the field of lighting and more specifically in the fields of colored lighting and variable intensity lighting.
Related Art
The art includes three-way bulbs configured to operate in lighting fixtures configured to power these three-way bulbs. See for example, U.S. Pat. No. 486,334 to Hall et al. These legacy lighting fixtures include a 3-way receptacle configured to receive a base of the three-way bulb. The receptacle typically includes two hot contacts and a neutral contact configured to form circuits when a three-way bulb is placed in the 3-way receptacle. The base includes contacts configured to come in contact with the two hot contacts and a neutral contact of the base when the base is screwed into the receptacle. The legacy lighting fixture further includes a three-way power switch to alternatively power the hot contacts. In operation the three-way switch alternatively powers the hot contacts such that the bulb is lit at three different output intensities.
FIG. 1 illustrates a Three-Way Bulb 100 of the prior art. Three-Way Bulb 100 of the prior art includes a Glass Cover 110 and a Base 120 configured to fit within a three-way bulb socket of the prior art.
FIG. 2 illustrates the three-way bulb of FIG. 1 with the glass cover removed. This view shows a First Filament 200 and a Second Filament 210. First Filament 200 and Second Filament 210 are supported by Leads 230A-230C.
FIG. 3 illustrates further detail of Base 120 of Three-Way Bulb 100. Base 120 includes three electrical contact elements. The three electrical contact elements include a neutral outer Contact Surface 310 often configured for screwing Three-Way Bulb 100 into a receptacle, a First Hot Contact 320 and a Second Hot Contact 330. When First Hot Contact 320 is powered (e.g. a voltage is applied relative to Contact Surface 310) First Filament 200 is lit. When Second Hot Contact 330 is powered Second Filament 210 is lit. When Both First Hot Contact 320 and Second Hot Contact 330 are powered, both First Filament 150 and Second Filament 160 are lit.
FIG. 4 illustrates a legacy Three-Way Receptacle 410 and Three-Way Switch 415 configured to accommodate Three-Way Bulb 100. Three-Way Receptacle 410 is characterized by including at least three contacts configured to make electrical connection to Contact Surface 310, First Hot Contact 320 and Second Hot Contact 330 of Three-Way Bulb 100. For example, FIG. 4 shows an instance of Three-Way Receptacle 410 including an Outer Contact 420, a Middle Contact 430, and a Center Contact 440. Often, Three-Way Receptacle 410 is further characterized by screw Threads 450 included in Outer Contact 420 and configured to receive Three-Way Bulb 100.
Switch 415 is configured to alternatively power First Hot Contact 130, Second Hot Contact 140, or both First Hot Contact 130 and Second Hot Contact 140. Various configurations of Switch 210 are known in the art. See for example, U.S. Pat. No. 551,357 to Beal or U.S. Pat. No. 712,149 to Paiste.
LEDs (light emitting diodes) are now available to that generate different colors of light. For example, white, red, yellow, green, and blue. These LEDs are of two general types. First, an LED that generates a fixed color (e.g., white or red or yellow). A variety of colors may be generated using more than one of these single color LEDs by powering them several at a time such that their outputs mix to produce a net light output. And Second, a multi-color LED that alone can generate more than one color responsive to voltages applied at different inputs to the multi-color LED.
FIG. 5 illustrates schematically several types of prior art LEDs 510.
The ability to generate light of different color is an advantage of the above LEDs. However, these LEDs require special fixtures. There is a need for improved systems and methods of using these LEDs that are more convenient and practical to consumers.